Faraday’s law in practice: If the speed of a straight conductor moving through a uniform magnetic field is increased while field strength and geometry remain the same, how does the induced voltage (emf) change?

Introduction / Context:Generators, sensors, and motion-based energy harvesting rely on electromagnetic induction. Faraday’s law tells us how induced voltage depends on motion. This question checks conceptual understanding of how speed affects induced emf when a conductor cuts magnetic flux lines.

Given Data / Assumptions:

• Uniform magnetic field, constant flux density.
• Conductor length and orientation are constant.
• Only the speed of motion is changed.

Concept / Approach:For a straight conductor of length L moving at velocity v perpendicular to magnetic flux density B, the induced emf is E = B * L * v. More generally, Faraday’s law states emf is proportional to the rate of change of flux linkage. If everything else is fixed, increasing v increases the rate of flux cutting and therefore increases the induced voltage proportionally.

Step-by-Step Solution:

Verification / Alternative check:Generator equations and lab demonstrations (sliding conductor on rails in a magnetic field) show emf rises with speed under constant field conditions and geometry.

Why Other Options Are Wrong:

• Not be affected / decrease / equal 0 V: All contradict E ∝ v for fixed B and L.

Common Pitfalls:Forgetting that only the velocity has changed; mixing up induced voltage with induced current (which also depends on circuit resistance and back-effects).

Final Answer:increase